<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ -->
    <title>Bootstrap HelloWorld</title>

    <!-- Bootstrap -->
    <link href="css/bootstrap.min.css" rel="stylesheet">


    <!-- jQuery (Bootstrap 的所有 JavaScript 插件都依赖 jQuery，所以必须放在前边) -->
    <script src="js/jquery-3.2.1.min.js"></script>
    <!-- 加载 Bootstrap 的所有 JavaScript 插件。你也可以根据需要只加载单个插件。 -->
    <script src="js/bootstrap.min.js"></script>
    <style>
        .inner{
            border:1px solid red;
        }

    </style>
</head>
<body>
    <!--1.定义容器-->
    <div class="container">
        <!--2.定义行-->
        <div class="row">
            <!--3.定义元素
                在大显示器一行12个格子
                在pad上一行6个格子
            -->
            <!--<div class="col-lg-1 col-sm-2 inner">栅格</div>
            <div class="col-lg-1 col-sm-2 inner">栅格</div>
            <div class="col-lg-1 col-sm-2 inner">栅格</div>
            <div class="col-lg-1 col-sm-2 inner">栅格</div>
            <div class="col-lg-1 col-sm-2 inner">栅格</div>
            <div class="col-lg-1 col-sm-2 inner">栅格</div>
            <div class="col-lg-1 col-sm-2 inner">栅格</div>
            <div class="col-lg-1 col-sm-2 inner">栅格</div>
            <div class="col-lg-1 col-sm-2 inner">栅格</div>
            <div class="col-lg-1 col-sm-2 inner">栅格</div>
            <div class="col-lg-1 col-sm-2 inner">栅格</div>
            <div class="col-lg-1 col-sm-2 inner">栅格</div>-->
            <div class="col-md-4 inner">栅格</div>
            <div class="col-md-4 inner">栅格</div>
            <div class="col-md-4 inner">栅格</div>

        </div>

    </div>

</body>
</html>